How to get a horseshoe crab in the mood

Persuading prehistoric-looking horseshoe crabs to mate in captivity may not be on most of our minds, but Carmela Cuomo from the University of New Haven spent 10 years figuring out how to get them in the mood. And it turns out all you need is some sand from home.

Horseshoe crabs look like a weird type of crab or lobster but are in fact relatives of spiders and scorpions and they’ve been around, looking like they do, for around abouts 450 million years.

But why breed them in captivity? Hopefully to take pressure off wild populations. Would you believe they are milked for their blue blood?